1. Field of the Invention
The present invention relates to an insert for photographic material processors, in particular for film or photographic paper.
2. The Prior Art
An insert of this kind, known from German Patent No. 2,609,463, is used for developing films or, in general, for developing photographic materials, such as photographic paper.
In this case, it is usual to transport the photographic material successively through several individual tanks in which there are different liquid chemicals. For complete development, the photographic material must be transmitted and transported from one individual tank into the following tank. To transmit the photographic material from one individual tank to the following, conveying the photographic material with conveyor belts from one tank into the other one has already been attempted. However, in this case, there is the danger that a chemical liquid of a certain kind might be transmitted from one individual tank into the following one. This can also happen through a passing conveying belt, such as that through which the photographic material must be transmitted. This contaminates the individual tanks, in a negative way, during a continuous process.
To reduce the transmission of chemical liquids from one individual tank to the following individual tank, the insert known from German Patent No. 2,609,463 provides using one single endless conveyor belt for this insert. This endless conveyor belt extends beyond the full width of the conveyor rolls, which are arranged in pairs at the input and at the output side of the insert. The lower roll at the output side works as a squeeze roll.
This known solution means that liquid will be squeezed out of the film material along its full width at the output side of each individual tank. Because the rolls that are arranged in pairs at the output side of the insert form a squeezing station (the lower situated roll works as a squeeze roll), the photographic or film material can be of different widths.
The known insert already provides a certain improvement. However, in practice, it has been shown that despite the presence of the squeezing station, totally satisfactory development cannot always be ensured. This is due to the fact that despite the presence of the squeezing station, small quantities of the chemical liquid of one individual tank still manage to get into the subsequent individual tank. Consequently, the film material cannot fully absorb the other liquid chemical contained by the next individual tank.